/**
 *    Copyright 2015-2018 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package com.google.code.kaptcha.text.impl;

import com.google.code.kaptcha.text.TextProducer;
import com.google.code.kaptcha.util.Configurable;

import java.security.SecureRandom;

/**
 * {@link DefaultTextCreator} creates random text from an array of characters
 * with specified length.
 */
public class DefaultTextCreator extends Configurable implements TextProducer {
    /**
     * @return the random text
     */
    public String getText() {
        int length = getConfig().getTextProducerCharLength();
        char[] chars = getConfig().getTextProducerCharString();
        // For safety, use SecureRandom instead of Random class
        SecureRandom rand = new SecureRandom();
        StringBuilder text = new StringBuilder();
        for (int i = 0; i < length; i++) {
            text.append(chars[rand.nextInt(chars.length)]);
        }

        return text.toString();
    }
}
